Vol. 41. Philosophical Magazine. April 1813. 



Contents of Number 180. 



XXXVil. An Investigation of the Properties of Lactic 

 Acid. By Jacob Keu7.eLius, Professor of Medicine and 

 Pharmacy, and M.R. A. Stockholm. Translated from the 

 Swedish ' - - - - -. - - - - 2tr 



XXXVIII. Critical Observations on Dr. Wollaston's 



' stated Improvement of the Camera Obsciira and Microscope 



in the Application of the Meniscus and two Plano-convex 



w;,,*. Lenses ; proving their Inferiority to the double Convex 



^^ Lens generally used. By William Jones, Optician - 247 



"^^ ', XXXIX. M. Montgolfier's Process for making White 



Lead. By Messrs. Clement and Desormes - - 253 



XL. An Essay on the Medical Effects of Climates. 

 From Dr. Young's "Medical Literature." - - 255 



XLI. On the Aurora Borealis. By Mr. B. M. FoksTER , 2G3 

 XLII. On Bread made from a Mixture of Wheat Flour ' 

 land Potatoes. By K. B. Way, Esq. of Eridport Harbour 265 

 XLIII. On Solids of greatest Attraction, or Repulsion 268 

 XLIV. On a Composition forming a Substitute for Port- 



*|^ land Stone. By Mr. Charles Wilson, of the Borough j 



!l,ofSouthwark '- 273i 



XLV. An Attempt to determine the definite and simple 

 Proportions, in which the constituent Parts of unorganic 

 Substances ilre united with each other. By Jacob Berze- 

 Lius, Professor of Medicine and Puarmacy, and M,R.A. 



Stockholm - - 275 '^-^ 



XLVI. Researches upon the Heat developed in Combus- 

 tion, and in the Condensation of Vapours. Read before 

 the Fiench Institute on the 24th of February and 30th of 

 November 1812. By Count Rum ford, FR.S. Lieut- 

 General in the Service of the King of Bavaria, Foreign As. 

 [sociate of the Imperial Institute of France, &c. &c. - 285 



XLVII. An Account relative to the Situation of His Ma- 

 'M jesty's late Ship Royal George, sunk at Spithead in the Year 

 i^ 17SiJ; together with the Value, and Means of raising her. 

 .^Br Mr. J. HiCKs, of No. 22, Charlotte Street, Rathbone 



iMPiace 297 



'My XLVIII. Poceedings of Learned Societies - -302! 



XLIX. Iiueiii!!;ence and Miicellancous Articles. — Mete- 



;;ical Table, Stc. 



! 16— 320/ 



^-vA *^* Communicalions for this Work, addressed to the Editor, 

 liyPickett- Place, Temple Bar, will meet with every attention. 



